The present invention relates to packaging for fragile structures such as printed circuit boards, disk drives, computer monitors or the like. More particularly, the invention relates to a flexible, thermally formed type of plastic packaging, of unitary construction, which is configured for supporting such fragile articles and for dissipating forces exerted upon shipping cartons containing such articles in such a manner that the articles are not damaged if the carton is dropped or mishandled.
Currently, the shipment of fragile articles, regardless of size and weight, requires special packaging to avoid damage to the articles. For this purpose, materials such as crumpled paper, nuggets of expanded foam, and/or preformed expanded polystyrene foam are used to package fragile articles, including but not limited to electronic articles such as computer monitors, radios, television sets, computer CPUs, computer disk drives, microwave ovens, VCR's and the like. The preformed polystyrene foam material is often provided in the form of "corners" or other support pieces which envelop at least portions of the packaged fragile article.
Aside from being bulky, upon an initial impact, the polystyrene foam loses virtually all of its shock absorbing qualities. Thus, fragile articles packaged with rigid pieces of expanded polystyrene foam as the protective media are susceptible to damage from repeated shocks to the box or container. A related disadvantage of such foam packaging is that a relatively thick piece of foam must be employed to protect a packaged article from impact, even though only a portion of the foam will be compressed upon impact.
Another disadvantage of conventional polystyrene foam is that its bulkiness requires packagers to allot significant warehouse storage space to the foam packaging elements prior to use. Also, shippers are required to select shipping containers, such as corrugated boxes, which are substantially larger than the article being packaged, merely to accommodate sufficient thicknesses of polystyrene foam which can absorb only one impact. Larger containers require additional warehouse space, both before and after assembly, and also take up more space per article shipped in rail cars or trailers.
Yet another disadvantage of conventional packaging for fragile articles is that because of its bulkiness, it is not generally economically feasible to ship the expanded polystyrene foam to a recycling location. Furthermore, even when the expanded polystyrene foam is recycled into product, the cost of recycling is relatively large and, generally, no more than about 25% recycled content can be utilized, with the remainder being virgin material. Indeed, considering the great quantity of expanded polystyrene foam which is currently in use to provide fragility packaging and the general lack of adequate recycling of this material, the adverse environmental impact is of staggering proportions. The present invention is directed to overcoming one or more of the above-identified problems.
Commonly-assigned U.S. Pat. No. 5,226,543 discloses a package for fragile articles which addresses the above-listed problems, and provides a solution in the form of a unitary package having a platform portion held a specified distance above the substrate by a peripheral wall formation which also borders the platform portion. Shock limiting formations are formed in the sidewall structure for restricting the movement of the platform portion toward the lower edge of the peripheral wall upon shock loading of the platform.
Commonly-assigned U.S. Pat. No. 5,915,976 discloses another type of thermoformable fragility package known in the industry as an "end cap" package. The package of the '976 Patent features collapsible crush buttons which depend from the article-retaining platform portion to provide additional shock absorption properties.
In use, it has been found that when packaged articles are relatively lightweight, the above-identified shock limiting packages may be too rigid or stiff. As such, the platform portion may not move a sufficient amount toward the peripheral wall upon shock loading, and the shock forces are absorbed by the packaged article instead of by the package.
It has also been found that conventional packages of this type do not exert enough gripping force on the packaged article to securely retain the packaged article.
Another disadvantage of conventional thermoformed fragility packaging is that in some cases, shock events are visible on the package as creases, folds, or other malformations which raise a suspicion in the consumer's mind that the product has been damaged, and thus detracts from the marketability of the article being packaged. It is believed that such malformations are the result of the package being overly stiff.
Accordingly, it is an object of the present invention to provide an improved unitary shock-resistant package for fragile articles which deforms to absorb shock loading even when the packaged article is relatively lightweight.
Another object of the present invention is to provide an improved shock-resistant package for fragile articles in which the deformability of the package is adjustable to suit the particular packaged article.
A still further object of the present invention is to provide an improved shock-resistant package which securely retains the packaged article, and may be configured to reduce visible malformations due to shock events.